The granularity of lime for desulphurizer with KR method is controlled within the reasonable and economic range of 0.5 mm to 1.5 mm.Based on granularity requirement of the lime for desulphurizer with KR method,this paper introduces the preparations and their main features and usage suggestions with relaxation screen,air separation crusher and column mill as the main equipments.

Increasing scrap ratio can stabilize steel putout and reduce iron and steel smelting cost，but it is very unfavorable to converter lining.Through statistics and comparison of various technical and economic index data of converters in the well-known domestic steel mills A and B，the adverse effects of increasing scrap steel ratio on converter lining and the formation reasons are briefly analyzed.

This paper briefly introduces the main types and smelting process of the electric furnaces for steelmaking,analyses the wear mechanisms of refractories used by electric furnaces and summarizes the main types of refractories used in various parts of the electric furnaces.Then it emphatically describes the development and application of refractories for steelmaking electric furnaces and points out their main development direction.

Overburnt and accretion are common phenomenon during limestone in lime kilns.In this paper,the causes,treatment and prevention measures of accretion are comprehensively analyzed,which can effectively reduce the incidence of accretion.

This paper introduces a pressure stabilizer for heat treatment carburizing furnace.The problems of unstable furnace pressure, obvious deformation and local soft point in refractory die during carburizing process are basically solved.The aims of stabilizing the quality of the mould, improving the production efficiency and reducing the cost are achieved.

This paper studies the expansion joints setting,selection of filling material for expansion joints and PVC expansion joint plates fixing method.The results show that the reasonable expansion joints setting and expansion joint plates fixing are helpful to eliminate the hidden dangers,such as the materials peeling off causing by lacking sufficient expansion space during furnace oast,and are more beneficial to prolonging the service life of the furnace.

It is well known that the electric component would cause harmonic interference to electric grid.Frequency converter is a typical electric component.A number of high capacity motors controlled by frequency converter are used in double shaft kiln,which generate harmonic interference to busbars.To avoid the problem,a typical systematic diagram for power supply of double shaft kiln is established by ETAP software plus the function of harmonic analysis,which can help us get total voltage distortion rate of L.T.busbar and accurate frequency spectrums for different harmonic contents.

By using light-burnt forsterite,magnesite clinker and fused magnesite as main raw materials,phenolic resin as binder,magnesium-forsterite dry material was prepared,and the effect of addition of sodium tripolyphosphate on properties of the dry material was studied.The results showed that the addition of sodium tripolyphosphate could effectively improve the flexural strength and compressive strength of the dry material,and improve the slag resistance within a certain range.